- Scientists think they have solved the 2,200-year-old mystery of the Antikythera Mechanism.
- The ancient device, found in a shipwreck, probably followed the Greek lunar calendar.
- They used statistical modeling techniques typically used to study ripples in space-time.
Last year, Graham Woan knew how he wanted to spend his Christmas vacation: trying to solve the 2,200-year-old mystery of the world’s oldest known “computer.”
The bronze device, known as the Antikythera Mechanism, is a mechanical computer with interconnected gears. In the second century BC, the user would use its rings and evenly spaced holes to map future celestial events such as eclipses.
But how many of these evenly spaced holes there were is a mystery and the key to determining exactly how the computer worked.
YouTuber Chris Budiselic has long been fascinated by the mechanism and started building his own version seven years ago, but wasn’t sure how many holes to include.
Based on some of Budisic’s published research, astronomers at the University of Glasgow, including Woan, he turned to statistical modeling techniques to find the answer.
“This struck me as an interesting problem, and I thought I could solve it in a different way over the Christmas holidays, so I started using some statistical techniques to answer the question,” Woan said in a university news release. .
Based on the number of holes, the researchers found, the device follows the lunar calendar instead of the Egyptian one, as some previous research had suggested.
A shipwreck full of ancient treasures
The Antikythera Mechanism is just one interesting find from a 2,000-year-old shipwreck first discovered by divers in 1900. Divers waiting out a storm found the remains near the Greek island of Antikythera.
According to the Woods Hole Oceanographic Institution, the excavation uncovered three life-size marble statues of horses, coins, jewelry and other treasures. But the Antikythera Mechanism is perhaps the most unique discovery of all.
It’s about the size of a shoebox, broken into six pieces, and has been eroding since it was underwater. The mechanism is so sophisticated that some have thought it must be a modern device that, according to Derek John de Soll Price, has mixed in with ancient artefacts. In the 1970s, he helped discover the device’s function.
X-ray images from 2005 provided researchers with new details about the device. And in 2020, Budiselic and his colleagues used the images to measure the positions of the holes and suggested that the mechanism had between 347 and 367 holes. If it had closer to 350 holes, it would follow the lunar calendar. If it had 365, it would be modeled after the Egyptian calendar.
However, it was difficult to determine the exact number due to the deteriorated condition of the equipment.
After learning about Budiselic’s research, Woan first used Bayesian analysis, calculating different probabilities of the total number of holes based on the position and number of holes in the remaining bronze pieces. He found that a device is a hundred times more likely to have 354 holes than 360 holes.
Woan’s colleague Joseph Bayley followed up on the research by modifying techniques used to study gravitational waves, which are ripples in space-time. His results agreed with Woan’s; there were probably either 354 or 355 holes in the ring.
In other words, there is a much higher probability that the mechanism followed the Greek lunar year instead of the Egyptian. He was able to calculate the positions of the planets with incredible accuracy for his time.
This find reinforces the impressive craftsmanship and knowledge required to create the device. “The exact location of the holes would require highly precise measuring techniques and an incredibly steady hand to punch them,” Bayley said in a press release.
Both published their research in the peer-reviewed Horological Journal.